User talk:Ajrocke

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Contents 1 Law of Mass Action 2 Kolbe 3 Using R to refer to side chains 4 Quiet revolution? 5 howdy!

[edit] Law of Mass Action

I found you on V8rik's discussion page and hope you can help with some historical stuff, even if it's not organic. It concerns the development of the law of mass action. In the original paper (1864) Guldberg and Waage stated that

"The substitution force, other conditions being equal, is directly proportional to the product of the masses provided each is raised to a particular exponent"

At some point later "substitution force" was replaced by "rate of reaction". I would like to know how this came about and in particular if the kinetic definition was introduced by G & W or by someone else. I think it might have been Van't Hoff (Berichte, (1877), 10, 669?), but in his book Studies on Chemical Dynamics he attributes the idea of forward and backward reaction rates being equal to one Pfaundler, without reference.

There are lots of ramifications around this subject, including the fact that the reaction rate definition of an equilibrium constant is not universally valid since rate equations do not, in general, follow the stoichiometry of the reaction. Petergans 07:18, 13 June 2007 (UTC)

[edit] Kolbe

Read this one?:

• E. von Meyer (1884). "Obituary Zur Erinnerung an Hermann Kolbe". Journal für Praktische Chemie 30 (1): 417 - 467. doi:10.1002/prac.18850300143.  His attacks on the French and on Kekule Baeyer and the rest of the structural chemists is quite amusing, but shows a certain lack of social behaviour.--Stone 13:51, 7 November 2007 (UTC)

[edit] Using R to refer to side chains

For a long time, there has been a "citation needed" in the side chain article regarding the origin of R. Does it come from radical, rest, or something else? I figured that, as an expert in 19th-century organic chemistry and structural theory, you are probably the best person to ask. :-) --Itub 15:28, 7 November 2007 (UTC)

Thanks for your reply. I also have assumed that it comes from radical (I don't buy the "rest" theory), but so far I haven't been able to find any solid sources on that. --Itub 16:31, 7 November 2007 (UTC)

The problem with "Rest" or "Residue" is that it does not correspond to a likely term that was actually used by chemists. "Rest", of course, means remainder or residue in German, but the more usual term used by German chemists was "Radikal" -- also an "R" word, and one that was far more likely to be used in this context. And of course it is corresponds to the English cognate, as well. Ajrocke 16:50, 7 November 2007 (UTC)

[edit] Quiet revolution?

Thanks for your help with the Kolbe article and Wöhler, and earlier with the Kekulé article and Kolbe. I am curious about one other question - what is the meaning of the phrase "Quiet Revolution" in the title of your book about Kolbe? This phrase intrigues me because I am from Québec, where La Révolution Tranquille is used in a very different context. Dirac66 (talk) 02:41, 16 December 2007 (UTC)

I thought of this phrase (which, I subsequently learned, has been used in other ways at other times) to designate a series of related theoretical transformations in the science of chemistry during the 1850s. When modern chemists look at chemical journals and textbooks ca. 1845, they can seem very strange and misguided. By contrast, many journal articles and textbooks of ca. 1865 can be readily read and understood today. Just to give one indication, most chemists ca. 1845 still thought that a molecule of water had only one hydrogen atom in it., and this single "error" had a cascade of implications throughout the science of chemistry. The reason why I called the revolution "quiet" is that neither chemists of that day, nor subsequent historians of science, had drawn much attention to these rather dramatic changes. They seemed to happen under everyone's nose, without being very explicitly noted. There is much more about all this in my book! Ajrocke (talk) 15:50, 16 December 2007 (UTC)

Re your example, I can see that correct formulas were necessary to further progress (such as structures). Modern first-year books mention that Cannizzaro showed how to establish correct atomic weights in 1858, but I suppose that chemists also took many years to gradually assimilate this idea. I do recall seeing an 1866 paper by Berthelot whose hydrocarbon formulas all have twice the correct number of carbons ("marsh gas" C₂H₄, benzene C₁₂H₆, etc. etc.), apparently based on an atomic weight of 6 for carbon. This paper had no structures and no mention of Kekulé. Dirac66 (talk) 23:21, 16 December 2007 (UTC)

[edit] howdy!

Alan, thanks so much for the letter you wrote that appears in the latest HSS Newsletter. I've been surprised at (and pleased with) how consistently positive the reactions have been to my article in the previous edition. You might be interested in the new May 2008 issue of the WikiProject History of Science newsletter, which is an attempt to let project members know about what history of science editing has been going on lately. Yours in discourse--ragesoss (talk) 23:56, 2 May 2008 (UTC)